Ferromagnetic material is utilized to manufacture a non-volatile memory device, such as magnetoresistive RAM (MRAM). Since its discovery in 1970, the tunneling effect of the magnetic tunnel junction (MTJ) has caused a dramatic change in the use of magnetic memory devices. The MTJ usually consists of at least three layers, which are the pinned layer, the barrier layer and the free layer. As a result, the stored memory in the domain can be written or read by sensing the current tunneling through the barrier.
The correctivity or the ratio of the self spin-polarization is one of the major concerns regarding the efficiency and accuracy of when to read or write the memory storage domain. One possible reason for the degraded performance is attributed to the damage on the film during manufacturing. Etching or plasma bombardments attacking the exposure surface during the process or oxidation of the post-etched film surface are probable factors. It was reported that even introducing a cap layer, such as silicon nitride, on the device right after the etching process would cause degradation. Therefore, in order to improve the performance of a magnetic memory device, the process of repairing the damage or reducing the oxidation of the device is essential.